Use a dedicated email
To solve sending and receiving problems, the best solution is to use a specific and dedicated email with less stringent limits. Our offer @ shopemail.it is designed for small ecommerce and to contain the costs of this type of email. With an hourly limit set at 200 emails / hour and with a specific configuration to obtain a high trust score from the anti-SPAM filters, it is the solution suitable for most online stores.
Unfortunately, the fight against SPAM makes sending emails very complex and arrival at their destination is never guaranteed even when no error messages are received in response.
An email dedicated exclusively to this purpose allows you to limit the problems as much as possible.